1. Field of the Invention
The present invention relates to an image forming system and an image forming apparatus, for forming an image in accordance with a received job.
2. Description of Related Art
An image forming apparatus, such as a multi-function peripheral, has a print function for printing an image on recording paper in accordance with a job received from a personal computer (PC). In case a plurality of jobs are received by the image forming apparatus, the image forming apparatus temporarily holds the jobs in a RAM (Random Access Memory) and prints an image on the recording paper by executing the held jobs sequentially.
In Japanese Patent Application Publication No 2007-210171, the following image forming apparatus is disclosed. In the image forming apparatus, while a specific print job is executed in the execution order which is previously set, a user operates a priority print key. Thereby, the specific print, job is stopped and another print job is preferentially executed.
Japanese Patent Application Publication No. 2007-326267 discloses an image forming apparatus in which the print jobs can be held with respect to each user and the user can designate the jobs to be successively executed. Therefore, the user can consciously instruct the image forming apparatus to execute the jobs successively to a certain extent.
For example, in a file prepared by a spreadsheet software (hereinafter, referred to as “spreadsheet file”), there are a plurality of sheets. In case that the plurality of sheets are collectively printed, the user sets the “print what” to a plurality of sheets (for example, “Active sheet(s)” or “Entire workbook”) by using a printer driver and transmits the print job to the image forming apparatus.
At this time, despite the user's intention, the print job is divided into a plurality of jobs and each of the plurality of jobs is transmitted to the image forming apparatus at an irregular time interval. When another user transmits a print job to the image forming apparatus during the irregular time interval, the print job transmitted by another user is inserted into the plurality of jobs. As a result, there was a problem that the printed document of one user is mixed with that of another user.
However, in the above Patent Application Publications, the specific means for solving the above problem are not disclosed. In particular, in case of the image forming apparatus disclosed in Japanese Patent Application Publication No. 2007-326267, the user can consciously set the image forming apparatus so as to execute the jobs successively to a certain extent. On the other hand, when a plurality of sheets of a spreadsheet file are collectively printed, the user hardly recognizes that a print job is divided into a plurality of jobs. Therefore, the user hardly sets the image forming apparatus consciously so as to execute the jobs successively to a certain extent.
Further, in the above Patent Application Publications, the technology for holding a plurality of jobs in a RAN or the like of the image forming apparatus is disclosed. The above problem is caused by transmitting a plurality of jobs into which a print job is divided, to the image forming apparatus at the irregular time interval. Therefore, even though a plurality of jobs are not necessarily held in the image forming apparatus, the above problem is possibly caused. In the Patent Application Publications, the above problem could not be solved.